This invention relates to a new recreational surface, and more particularly to a scheme for interlocking the tiles which make up the recreational surface.
Statistics from the United States Consumer Product Safety Commission indicate that the majority of playground-related injuries are caused when children fall from equipment and strike the underlying surface. Nearly half the injuries that result from falls are to the head, and range in severity from minor bruises to skull fractures, concussions, brain damage, and even death. Studies indicate that, while they may require little maintenance or repair, hard surfacing materials such as asphalt and concrete do not provide adequate injury protection from accidental falls and are therefore unsuitable for use under playground equipment. Another type of surface which is commonly used around playground equipment is a layer of loose material such as bark nuggets, bark mulch, shredded bark or cocoa shell mulch. The cushioning potential of these materials depends upon the air trapped within and between the individual particles. Therefore, when the materials decompose or become pulverized over a period of time, or mix with dirt, they tend to lose their cushioning effect. Cushioning protection also decreases in rainy or humid weather when the materials absorb moisture and become packed down, or if the temperature drops and the wet materials freeze. Furthermore, because strong winds can erode these materials, thereby reducing the thickness available to protect against injury, and because the playing action of children can push the protective materials away from fall areas, frequent grading and leveling are necessary to maintain sufficient depth to provide the necessary protection.
Certain other types of loose materials, for example, sand, pea gravel and shredded tire rubber, are also used around playground equipment. As with the previously mentioned surfacing materials, however, these materials also require frequent leveling to replace material that is pushed or blown away from fall areas, and grading or sifting to remove foreign matter. Also, moisture tends to make these materials more cohesive and therefore less cushioning. For example, sand loses virtually all resiliency when it becomes wet.
Another category of surfacing materials includes outdoor rubber mats, foam rubber gym mats and synthetic turf. Generally, the cushioning properties of these materials will depend upon the foundation or surface over which the material is installed. Although surface materials of this type require very little maintenance, they are oftentimes the subject of vandalism, such as removal or displacement.